One can liquidate a multi-million dollar portfolio in seconds without detecting a blip in the market. 

Honeywell makes one with a four foot lead which can detect water at any point along the sensor, allowing loops around water heaters, washing machines, or piping.I checked Consumer Reports and there is no testing or report for this product.  

Although I concur with Bill Gulley ' post I detected that he was being sarcastic.

And, in the case of AML, there are criminal penalties attached to not detecting, not filing, and not keeping reporting confidential.

A private detective may also be able to help.

Why were homicide detectives called if nobody died? 

Install some motion detected lights around the building, and some decent quality cameras, also purchase a firearm for your protection. 

But how many of us stop to think about just where the CO detect should go? 

Make sure the inspector has a thermal camera which can detect hidden moisture inside walls. 

Most radar and laser guns don't emit continuous signal, so they can be hard to detect.